Propeller shaping machine



Jam 7, 1941. w. G. DUNN I PEOPELLER SHAPING MACHINE Filed Sept. 23, 1937 .3 Sheets-Sheet 1 www:

Jan. 7, 1941.

W. G. DUNN PROPELLER SHAPING MACHINE Filed Sept. 25, 1957 3 Sheets-Sheet 2 j ,9v m4 w w w Jan. 7, 1941. w; G. DUNN PROPLLER SHAPING MACHINE Filed Sept. 23, 1957 3 Sheets-Sheet 5 Patented Jan. 7, 1941 UNITE-D STAT-Es PATENT :ofFFelzcE ,PROPELLER SHAPIN G MACHINE vWiuiam G. Dunn, clarinaa', Iowa Application September 23, 1937,. Serial No; 165,364

- comparatively'simple in: construction, yet effective .f

Y- inits operation. I A- furtherfobjectis'to provide av machine in which la pair of `prcpellerlblanks maybe clamped, l`and-.having amandrel `-for shaping the front of one of the blanks and the back of the other, .the propellenblanksibeing rmounted on a-carriage, -means beingV provided for moving the carriage and thus feeding the. blanksalongrthe shaping knives. -f A further object is` to -providemeans for separatingthe shaping knives from the blankadjacent l5Av` the hub ofthe blank, whereupon theV carriage may be returned and the/blanks adjusted foranother shaping operation thereon. u A furtherobject is to provide amandrel having two sets,l of knives, one for-shaping the compara- 2.0

. .other Vfor shaping .the back of 4lthe blade with an fair-foil contour, the line of rtravel ofthe blank` Vlying in lengthwiseinclined -position on the carriagefas it passes under the knives beingy such as the blank.

A further object is to providemechanism which is partially automatic Afor advancingi the carriage and stopping it whenthe bladehas beenshaped 30 Yto .the hub portion of the blank.

. With/,these and other Uobjects in-view, my inventicnA consists in theconstruction, arrangement .1 and Acombination of they various parts of my propellershaping machine, whereby theobjects: cona `templated are attained, as hereinafter more fully set.: forth, pointedY out in my claims, and illustrated inthe accompanying drawings, in which:

Figure 1 is a yplan View of a propeller shaping machine embodying `my invention. 40 Figure 2V is a front elevation of same, parts f thereof being broken away and otherparts being lshown inv section to illustrate details of construction.

Fig. 3 is a-diagrammatical View of a blank after 45 the 'rst shaping operation has been performed thereon. i Figure 4 is a similar diagrammatcal vview of the blank after the second shaping operation has -f been performed thereon.v 50 Figures 5 and 6 are diagrammatical views of the blank Vafter the lthird and fourth shaping operations have been performed thereon, Figure 6 lillustrating the completed blade.

Figures 7, 8, 9, 10 and 11 are sectional views 55 on the lines 'l-"I, 8 8, 9 9, Ill-I0 and Il-ll respectively of Figure 3.

Figures 12, 13, 14, and 16 are sectional views on the lines I2-l2, I3-|3, l4-l4, l5-l5 and |6-l 6 respectively of Figure 5.

Atively flat front ofthe propeller blade, and the 1r to taperwthe blade inthickness from tip to hub of AFigures 17,- 18; 19, 20 and 21A are *viewsicorre-M (CIL 144-143) .vsponding'to Figures 12, 13,14, 15 and'16. respectively--showing `the formation of. a propeller in a modified type of .my .machine designedyfor producing .a progressive change in pitch of theblade fromtip to hub of.the;blank, or to, provide a blade with: helical pitch.

Figure. 22 is a vertical sectional View of a modied form of machine, taken on theline 22 22 of Figure24.

Figure 23 is a. sectional View on the line 23--23 of Figure 22.

.Figure 24 is aplan View` of the modified form of machine.

4Figure 25 is avertical elevational View partly in section'. taken on the line. 251-25 of Figure 24.2.

On the accompanying drawings Ifhave used the v reference character FA to indicate, lgenerally a .,frame, 0.a carriage and M a mandrel.

. Thefra'me Fmay be suitably supported such as The .mandrel M ismounted on a shaft'26 and .carries two sets of Shaper. knives 2l Aand 28. In Figure 1 the shape of each knife 27 is illustrated, whilethe'shapes of Ythe knivesg28 are illustrated `.therelative plane-like frcntface of apropeller blade, .While the knives 28 are vfor forming the back of..the `bladewith an air-foil contour.

For rotating'the mandrel, M I provide ka prime mover such as .an electric motor 29 having `a pulley-30.. The pulley 30 is operatively connected by a belt 3l to a driven pulley 32 onthe shaft 26. The shaft 26 is mounted in bearings 33 carried by asub-frame 34. The sub-,frame 34 is pivoted asby a pinv35 to the-frame F. A pair of stop.

screws are provided which Vnormally contact withstop arms 3l ofthe sub-frame 34, such normal'contact being provided by springs 38.

-The springs 38 are mounted on rods 39 having their lower ends anchored in the frameF and which2 extend upwardly .through perforations in the stop arms 31 vand terminate in heads 46. The springs 38 are interposed between the heads 48 and the stop arms 3l. The stopscrews 36, of course, are adjustable so that the height of the knives 21 and 28 relative to the carriage C may be varied as desired.

Manualmeans is provided for imparting'pivotal movement to the sub-frame 34 againstV the bias of the springs 38 comprising a crank 4| for rotatinga cam 42. When the crank 4I is swung clockwise, the lobe of the cam 42 will engage the sub-frame 34 and raise it. Uponrelease of the crank, the springs 38 will return the sub-frame to its initial position. v f

Thecarriage C comprises ,av plate 43 having at its sides guide--beads 44. The Vguide beads 44 travel in guideways 45 in the sides of. the 'frame F.

v For manually imparting longitudinal lmovement by legs 24resting on afloor surface. or thelike 23;

indottedlines.L The. knives 21 are for forming,

to thelcarriage C rela-tiveto the iframe F, I proavide a crank 46 for rotating a pinion 41. The pinion 41 coacts with rack teeth 48 on the bottom of the carriage C. At the forward end of the rack teeth a'stop projection 49 is provided for limiting return movement of the carriage.

For automatically moving the carriage C I provide at its forward end a pair of ears 50. Cables 5l are connected with the ears 50 and are adaptable for winding on a drum 53. The drum 5311s loosely journalled on a shaft 54, but may be operatively connected therewith by a jaw'clutch 55. The clutch 55 may be slid along the shaft 54 (relative to which it is slidable and'nonrotatable) by a yoke 56. The yoke 56 is pivoted-at.51 to a bracket58 extending from the frame F.

A rod. 59 is connected with an arrm 60 of the yoke 56 for manually engaging the clutch 55. The rod 56 extends through a slot 6l of the frame F and to a bearing box 62 relative to which it is slidably mounted. The rod then terminates in an upwardly extending handle portion 63 which may be moved toward the right for engaging the clutch 55.

The shaft 54, and thereby the clutch 55, is driven from the motor, 29 by a belt 64 extending around the shaft of the motor and around an enlarged pulley 65 mounted on the shaft 54. Obviously when the motor 29 is rotating and the clutch 55 is engaged, the cables 5I will be wound on the drum 53, for thus automatically advancing the carriage C.

When the forward end of the carriage engages an extension 66 of the yoke 56, it Will move the jaw clutch 55 to the disengaged position shown in Figure 1, thus automatically preventing any excessive movement of the carriage and consequently breakage of the Cables 5I or other parts of the machine.

The carriage C also carries a pair of cams 31 to engage the stop arms 31 an-d thereby automatically raise the sub-frame 34 to disengage the knives 21 and 28 from the propeller blank as the carriage approaches its forward limit of movement, as will hereinafter appear.

On the carriage C I illustrate a pair of propeller blanks P and P. These may be securely clamped in position by a clamp bar 61 across their hub portions, toothed jaws 68 at the forward ends of the propeller blanks and adjustable clamp jaws 69 at their rear ends. The clamp bar 61 is clamped in position by wing nuts 10 mounted on threaded rods 1I extending from the plate 43. The clamp jaws 59 are slidably mounted in housings 12 extending upwardly from the plate 43 and having hubs 13.

Wing set screws 14 are threaded in the hubs 13 for urging the clamp jaws 69 toward the propeller blanks P and P and forcing the forward ends of the blanks against the toothed jaws 68.

Practical operation In the operation of my propeller shaping machine, a blank of rectangular cross section, as shown by `dotted lines in Figures '7 or 17, for instance, is preferably cut to the shape illustrated in Figure l, that is with its ends or the tips of the blades narrower than its central or hub portion. The propeller blank P is first laid flat on the plate 43, as shown in Figures 1 and 3, whereupon the carriage C is advanced either by the crank 46 or the cables 5I, while the mandrel Mis rotating in the direction of the arrow in Figure 2.

The-knives 21 will progressively cut away the upper face of the blank P as shown in Figures '7 to 1l inclusive, the shape in Figure '7 being at the tip of the blade and the shape in Figure 11 being adjacent the hub of the propeller blank.

The blank will then appear as in Figure 3.

the knives 21, the clamps 61 and 69 are loosened and the blank reversed end for end, whereupon 10 the other end may be formed as shown in Figures '7 to 11, and the blank will then appear as in Figure 4. The blank is then turned over and placed in the position of the blank P in Figure 1. So that'it will be thinner at the tip than at the l5 hub, as illustrated in Figures 12 to 16, and to avoid having it produce thick edges at the tip of the blade as shown in Figure '7, I arrange a iiller block 15 on the plate 43 for the forward end cf the propeller blank (see Figure 5), or the top of the plate 43 may be formed in .this shape.

After the operation shown in Figure 5 has been completed, the blank is turned end for end to produce the finished propeller, as shown in Figure 6, the hub portion thereof being indicated by the bracket 'i6 and the blade portions by the brackets 11.

Shaping the propeller blank by the machine as thus described, produces a propeller of the desired cross sectional shape from hub to tip as 0 illustrated in Figures 12 to 16, but one which does not have a helical pitch.

It is possible, however, to give helical pitch to the propeller by the mere expedient of progressively inclining the carriage laterally as it moves along the frame F. This is accomplished by the construction shown in Figures 22 and 23, wherein a pair of carriages are provided for the blanks P and P', one comprising a plate 43 and the other a plate 43". The guideways for these plates are indicated at 45 for the plate 43 and 45 and 45" and for the plate 43".

Figure 23 illustrates how one of the guideways for the plate 43 is level and the other is formed in two sections, each of which is inclined so that its forward end drops relative to the rear end thereof. This progressively inclines the carriage laterally from the position almost level across at the end to a position somewhat like that shown for the plate 43" in Figure 22, near the hub. These plates have pairs of rollers 18 at the positions indicated at the arrows 22 and 22a in Figure 2, and which roll along the guideways 45 and 45". This progressively inclines the blank laterally as indicated by dotted lines in Figures 1'7 vto 21, level position being indicated by the line L which is at a predetermined position from the axis of rotation of the mandrel M.

It will be noted ithat'the inclination of Ithe blade shown in section in Figures 1'7 to 21 varies so that its pitch is less in Figure 1'7 at the .tip of the blade than in Figure 2l adjacent the hub thereof. The variation in depth of the cut of the knives 28 effectively shapes the propeller blade down to a thin cross section at the tip and a thick one .at the hub, yet preserves the airfoil contour o-f the back of the blade throughout, as is obvious fro-1n an inspection of Figures l2 to 21.

The cross sectional shape and pitch of :the blad-es are automatically secured with my machine, it being merely necessary to clam-p the blanks in position with such spacers ais-may be needed .and feed them Sto the knives 21 and 28.

In theA modified form of my machine as shown 75 particularly in Figures 22, 24 and 25, a means is illustrated of cutting a taper on the lblade and also tilting the blade laterally to cut .a helix. 'Io accomplish this there is provided on the carriage 43' a clamp 61 and on the carriage 43" a clamp 61 so that the blanks P and P respectively may be separately clamped to their respective carriages by means of a combined bolt and win-g nut 10 .at the end of each clam-p. The blank P travels in `a straight undeviating path underneath the cutters 21 as described in connection with the preferred form of my device, except that when desired a tapered wedge may be placed beneath the blank in order to lift .the right han-d end slightly so that the longitudinal axis is tilted. In a similar manner the blank P is secured upon the carriage 43 in a tilted position longitudinally by use of a tapered spacer 'l5'. The tapered spacer is thicker at the right hand end as viewed in Figure 25 than at the left so that the blank P will be tilted higher at the right end than at the left. Since lthe right end wi-ll be closer to the rotating mandrels 28 than the portion near the hub more material will be cut from the end, thereby producing a .thinner section at the tip than at the hub. The motion of the `carriage in a direction from left .to right covers only a distance of half the length of the blank so that one side only is cult at -a time.

At .the same time a taper is being cut on the blank the 4carriage is likewise being inclined laterally. Since the guidevvay 45 is horizontal the roller 13 which lies within it will cause the right hand side of the carriage 4'3" as viewed in Figure 22 to travel in a horizontal plane. At the saine time the rollers 'I8 which lie respectively one in each of .the inclined guideways 45 will gradually raise the left hand side of the carria'ge 43", as viewed in Figure 22, as the carriage passes from lett to right as Viewed in Figure 25.

The two guideways 45 have precisely the same alignment and are provided in duplicate so that the rollers 18, one alt each end of the carriage, will be raised simultaneously by equal amounts. At the start of movement of the carriage from the position shown in Figure 25, the blank P will have a pronounced lateral tilt somewhat as shown in Figure 22. At the same time the right hand end will be closer to the mandrel 28 because of the tapered spacer 15' and the mandrel will cut lthe blank .to the shape shown in Figure 17.

As the carriage 43 passes from left to right the rollers 'I8 will gradually climb upward in the guideways 45", thereby progressively lessening the lateral tilt as shown in Figures 18, 19 and 20. At the same time, however, the tapered spacer 15 will be gradually lowering the position of the blank relative to the mandrel 2-8 so that a lesser quantity of material will be cut from the adjacent side of the blank until the blank portion near the hub will be shaped to a form somewhat like that shown in Figure 2l.

It will thus be apparent that the blank of the propeller blade can be tapered as to thickness from a ratherthin dimension at the tip to a rather thick dimension at the hub at the same time as a variable contour is cut upon the rear side of it.

In operation, the first blank is cut on both ends by .the knives 21 and then transferred :to the position of the blank P', and a second blank placed in the position of the blank P. Thereafter as the carriage C is advanced, two blanks may be worked on Iat .the same time, the front of one being shaped by the knives 2l and the back of the other being simultaneously shaped by the knives 28. It is accordingly possible to quickly shape the blades of th-e propeller blank after it has once been cut to its desired contour.

With va machine of the character disclosed, the production of propeller blades of the proper pitch and cross sectional shape is facilitated to a degree making it possible for one man to turn out a considerable volume of perfectly shaped blades in a days time.

Some changes may be made in the construction and arrangement of .the parts of my -device without departing from :the real spirit and purpose of my invention, and it is my intention to cover by my `claims any modie'd forms of structure or use of mechanical equivalents, which may be reasonably included within their scope.

I claim as my invention:

1. In a propeller shaping machine, a frame, means for supporting a pair of propeller blanks thereon for longitudinal movement, a shaft, a pair of jointly operable shaping elements for the propeller blanks spaced on opposite sides of the center of said shaft, one being shaped for forming the front oi one of the blanks and the other being shaped for simultaneously forming the back of the other blank with an air-foil contour, means on the frame for incl-ining one of said propeller blanks laterally during its longitudinal movement to thereby `change the pitch of said propeller blade from tip to hub olf the propeller blank.

2. In a propeller shaping machine, a frame, a carriage movable relative thereto, means for clamping a pair of propeller blanks on said carriage, la mandrel rotatable in fixed position having a knife for shaping .the front of one of said propeller blanks and a knife for simultaneously shaping the back of the other propeller blank with .an air-foil contour, and means engaged by said carri-age at one limit of its movement to disengage both said knives from said propeller blanks adjacent the hub portions thereof.

3. In a propeller shaping machine, a frame, a carriage mounted on said fram-e for movement in -a straight line within a horizontal plane, means including a tapered spacer beneath a propeller blank for clamping said propeller -blank immovably relative to said carriage in a position such that the longitudinal axis of said propeller blank is inclined relative to the line of travel of .the carriage, a rotary mand-rel in the line of travel of .the propeller blank having la knife for shaping the contour of said propeller blank, means for moving said carriage and blank in a straight line perpendicular Ito the axis of said rotary mandrel so lthat the blank is in contact with the mandrel for progressively cutting a longitudinal taper on the blade of the propeller, and coacting guide means on said frame and said carriage respectively, one of which is inclined in the direction of travel of the carriage for progressively tilting said carri-age laterally during its travel to pro-gressively rotate the blade about its longitudinal axis and change .the pitch of the propeller blade being shaped.

WILLIAM G. DUNN. 

